This application is based upon and claims the benefit of priority from prior Japanese Patent Application P2001-67793 filed on Feb. 1, 2001; the entire contents of which are incorporated by reference herein.
1. Field of the Invention
The present invention relates to an electric component compression bonding machine and method.
2. Description of the Related Art
There have been known, as apparatuses for manufacturing, e.g., flat panel displays such as plasma display panels, electric component mounting machines which are used to mount the electric components composed of, for example, film-type elements and so forth.
FIG. 1 shows one example of a glass substrate pair on which electric components are mounted by means of an electric component mounting machine, in which FIG. 1(a) is a plan view and FIG. 1(b) is a side view thereof. The glass substrate pair 1 as illustrated in the figure is composed of two substrates 1a and 1b as joined to each other having different dimensions and shapes. On the lower surface of the upper substrate 1a and the upper surface of the lower substrate 1b, a plurality of electric components 2 are mounted along the respective sides of the substrates through anisotropic conductive film 3 (referred to as ACF hereinafter).
Also, in the case of this type of the electric component mounting machine for use in manufacturing glass substrate pairs, the lead electrodes of the electric components 2 are connected to the corresponding lead electrodes of the glass substrate pair 1 by affixing strips of the ACF 3 to the glass substrate pair 1 along the sides where the electric components 2 are to be mounted, temporarily securing the electric components 2 to the glass substrate pair 1 by means of the adhesivity of the ACF 3, and then thermocompression bonding the electric components 2 as temporarily secured to the glass substrate pair 1 by the electric component compression bonding machine.
FIG. 2 shows one example of an electric component compression bonding machine 10. The electric component compression bonding machine 10 as illustrated in FIG. 2 is composed of a pressure application tool 13 in the form of an elongated shape which is moved up and down by means of a pressurized cylinder 11 and provided with an embedded heater 12, a backup tool 15 located opposed to the pressure application tool 13 as a pressure receiving tool which is moved up and down by elevator means (not shown in the figure) and provided with an embedded heater 14, and a sheet member 16 located between the pressure application tool 13 and the backup tool 15. The sheet member 16 is located to intervene between the pressure application tool 13 and the electric components 2 during pressing the electric components 2 with the pressure application tool 13 and serves to absorb the disparity in the flatness of the pressing surface of the pressure application tool 13 in order to make it possible to apply a uniform pressure to the entirety of the area to be presses, and therefore is designed to cover the entirety of the pressing surface of the pressure application tool 13.
The pressure application process is performed by means of the electric component compression bonding machine 10 as follows. At first, the glass substrate pair 1 to which the electric components 2 have been temporarily secured in the previous step is placed on a substrate stage (not shown in the figure) and positioned to the appropriate location where compression bonding is carried out. In the case where the electric component 2-1 is the leftmost electric component among the group of the electric components which are arranged along the side of the glass substrate pair 1 to be pressed at this time, as illustrated in FIG. 2, the positioning is carried out in order that the left end xe2x80x9caxe2x80x9d of the electric component 2-1 is aligned to or located slightly inside of the left end xe2x80x9cAxe2x80x9d of the pressure application tool 13 (more exactly, the left end of the pressure application surface of the pressure application tool 13). Next, the backup tool 15 is moved upward to support the glass substrate pair 1 from the lower position as illustrated in FIG. 2, and thereafter the pressure application tool 13 is moved down by means of the pressurized cylinder 11. By this configuration, as illustrated in FIG. 2, the four electric components 2-1, 2-2, 2-3 and 2-4 located within the span of the pressure application tool 13 are thermocompression bonded to the glass substrate pair 1 at a time through the ACF 3 under the application of pressure by the pressurized cylinder 11 and the application of heat by the heaters 12 and 14.
After the thermocompression bonding of the electric components 2-1 to 2-4 has been completed, the pressure application tool 13 is moved up while the backup tool 15 is moved down. Next, in the case where the electric component 2-6 is the rightmost electric component among the group of the electric components which are arranged along the side of the glass substrate pair 1 to be pressed at this time, as illustrated in FIG. 4, the positioning is carried out in order that the right end xe2x80x9cbxe2x80x9d of the electric component 2-6 is aligned to or located slightly inside of the right end xe2x80x9cBxe2x80x9d of the pressure application tool 13 (more exactly, the right end of the pressure application surface of the pressure application tool 13). In the same manner as the previous procedure, after the backup tool 15 is moved up to support the glass substrate pair 1 from the lower position, the pressure application tool 13 is moved down in order to bond the four electric components 2-3, 2-4, 2-5 and 2-6 located within the span of the pressure application tool 13 by thermocompression.
Meanwhile, when the type of the glass substrate pair 1 to be handled by the electric component compression bonding machine 10 is changed, the dimensions of the glass substrate pair 1 and the electric components 2 will change as well as the intervals between adjacent electric components on the glass substrate pair 1 resulting in the shortcoming as illustrated in FIG. 5. Namely, in the case where the electric component 2-1 is the leftmost electric component among the group of the electric components which are arranged along the side of the glass substrate pair 1 to be pressed at this time. When the left end xe2x80x9ccxe2x80x9d of the leftmost electric component 2-5a is aligned to or located slightly inside of the left end xe2x80x9cAxe2x80x9d of the pressure application tool 13, the right end xe2x80x9cBxe2x80x9d of the pressure application tool 13 is positioned in the middle of the upper surface of the electric component 2-5a so that, as a result, the pressure application surface of the pressure application tool 13 can cover only part of the electric component 2-5a. Accordingly, if the pressure application process were carried out in this condition, the ACF 3 as located under the electric component 2-5a is affected by heat transferred from the pressure application tool 13 or from the backup tool 15 through the electric component 2-6a. Since the ACF 3 is made of a thermoset material, the portion of the ACF 3 as located under the electric component 2-6a but not located just under the pressure application tool 13 is hardened without pressure applied by the pressure application tool 13.
Because of this, even if an amount of heat and a pressure are applied to the portion of the electric component 2-6a having not yet processed in a later step, the lead electrodes of the electric components 2 can not be connected to the lead electrodes of the glass substrate pair 1 since the portion of the ACF 3 as located under the electric component 2-5a has already been hardened as described above. Accordingly, there occurs connection failure in that portion so that the glass substrate pair 1 becomes defective.
The shortcoming can be removed by exchanging the pressure application tool 13 for another one each time when the dimensions of the glass substrate pair 1, the dimensions of the electric components 2, the intervals between adjacent electric components on the glass substrate pair 1 and/or the like are changed. However, this solution is undesirable because it takes much time to replace and adjust the pressure application tool resulting in decreasing the rate of operation of the machine.
In accordance with an aspect of the present invention, the improvement resides in an electric component compression bonding machine for bonding a plurality of electric components to a substrate along a straight line, comprising: a pressure application tool for applying a pressure to said electric components; a pressure receiving tool located opposed to said pressure application tool; a substrate supporting tool for supporting said substrate between said pressure application tool and said pressure receiving tool; a moving unit for moving said substrate supported by said substrate supporting tool relative to said pressure application tool; a parameter setting unit for setting parameters relating to the arrangement of said electric components on said substrate; and a control unit connected to said moving unit and taking control of said moving unit with reference to said parameters as set by said parameter setting unit in order to adjust the position of said substrate supported by said substrate supporting tool relative to said pressure application tool for compression bonding said electric components to said substrate by said pressure application tool, wherein, while said plurality of electric components are divided into groups so that each of said plurality of electric components belongs to one of said groups, said compression bonding is dividedly performed a plurality of times for one after another of said groups in order that there is no electric component which is partially subjected to the pressure before compression bonding.
In accordance with another aspect of the present invention, the improvement resides in an electric component compression bonding machine for bonding a plurality of electric components to a substrate through a buffer element along a straight line, comprising: a pressure application tool for applying a pressure to said electric components; a pressure receiving tool located opposed to said pressure application tool; a substrate supporting tool for supporting said substrate between said pressure application tool and said pressure receiving tool; a buffer element supporting tool for supporting said buffer element between said pressure application tool and said substrate; a moving unit connected to at least one of said pressure application tool and said buffer element supporting tool for moving said pressure application tool relative to said buffer element supporting tool in said straight line; and a control unit for compression bonding said electric components to said substrate by controlling said pressure application tool.
In accordance with a further aspect of the present invention, the improvement resides in an electric component compression bonding method for bonding a plurality of electric components to a substrate along a straight line, comprising: a step of arranging said plurality of electric components along said straight line on said substrate; and a step of moving said substrate relative to said pressure application tool with reference to information about the positional relationship of said plurality of electric components on said substrate in order that said pressure application tool is moved to the position in which said pressure application tool can compression bond, in the vicinity of one end of said pressure application tool, the entirety of one of said electric components located closest to one end of said substrate, in which said pressure application tool can compression bond, in the vicinity of the other end of said pressure application tool, the entirety of one of said electric components located closest to said other end of said pressure application tool and in which the other end of said pressure application tool is located apart from one of said electric components located adjacent to said one of said electric components located closest to said other end of said pressure application tool.
In accordance with a still further aspect of the present invention, the improvement resides in an electric component compression bonding method for bonding a plurality of electric components to a substrate through a buffer element along a straight line, comprising: a step of arranging said plurality of electric components along said straight line on said substrate; and a step of moving said substrate relative to a pressure application tool to a position where said pressure application tool can perform compression bonding the entirety of one of said electric components located closest to one end of said substrate; and a step of moving said buffer element relative to said pressure application tool, before, after or at the same time as said pressure application tool moving step, in order that, during compression bonding, one end of said buffer element is located inside of said one end of said substrate and inside of one end of said pressure application tool close to said one end of said substrate.
In accordance with a still further aspect of the present invention, the improvement resides in an electric component compression bonding machine for bonding a plurality of electric components arranged in a row to a substrate, comprising: a pressure application tool for applying a pressure to said electric components; a pressure receiving tool located opposed to said pressure application tool; a substrate supporting tool for supporting said substrate between said pressure application tool and said pressure receiving tool; a moving unit for moving said substrate supported by said substrate supporting tool relative to said pressure application tool; a control unit connected to said moving unit and taking control of said moving unit in order to adjust the position of said substrate supported by said substrate supporting tool relative to said pressure application tool for compression bonding said electric components to said substrate by said pressure application tool, wherein said control unit controls said moving unit to adjust the position of said substrate supported by said substrate supporting tool relative to said pressure application tool in order that any one of the ends of said pressure application tool is positioned apart from said row of said electric components or positioned between adjacent ones of said electric components.